1971 280sl stalling when hot - Page 2 - PeachParts Mercedes-Benz Forum

Old World Auto · #16 09-17-2007, 09:22 AM

I side with Arthur on this one. You are expeiencing classic debis/rust in the flower pot. Quite common on these cars. Do the test he recommends. Of course, best to check the other basic items as well for peace of mind.

Richard Wooldridge · #17 09-17-2007, 03:15 PM

Excellent pictures, Chuck! I'm sure you've nailed the problem. I wonder if he ever tried my starting fluid idea, ie when it stops, run out and put some starting fluid in the air filter and see if the engine fires for a second or two... but your pictures show the most plausible explanation of the trouble he is experiencing.

Regards,

Arthur Dalton · #18 09-17-2007, 04:01 PM

<>

Where are those pictures ?????

aaown · #19 09-17-2007, 04:22 PM

Holy cow Arthur. Wow, ok. You sure know a lot about this vehicle. It all makes sense of course. I will do my best to follow your advice and let you know what I come up with.

Thanks for all your advice and time you have spent on the reply. And thanks for the pictures as well, they really help.

Al

aaown · #20 09-17-2007, 04:28 PM

Quote:

Originally Posted by Old World Auto

I side with Arthur on this one. You are expeiencing classic debis/rust in the flower pot. Quite common on these cars. Do the test he recommends. Of course, best to check the other basic items as well for peace of mind.

Well, I am going to give it all a try. This has been a challenge since I have not worked on German automobiles before. I hope this does it.

Thanks,

Larry Delor · #21 09-17-2007, 04:52 PM

Do the 108's have this flower pot as well?

Richard Wooldridge · #22 09-18-2007, 01:26 AM

Sorry Arthur!
I really meant YOU!! I guess I just looked at the previous poster without considering that it might not have been you by the time I posted a reply... I'll try to do better next time. At any rate, your explanation was both well written and very instructive, as were YOUR pictures!!

Best Regards,

Arthur Dalton · #23 09-18-2007, 10:09 AM

Thanks..
The pic of the opened tank is actually from JA over at the 113 Group. He is a Great asset to that group with his pictures tutorials.

For those who are following this thread , the screen filter on these MFI systems is located in the center of the Swirl Pot and it is accessed by removing the large Hex Head plug at the bottom of the tank.
Here is another trick I use for that plug . You simply invert a spark plug socket on an extension and you have the correct Tool...
Everyone always ask me where to get a hex tool for this job and I tell them they have one right in their tool box, but they just don't know it ...

Here it is :

http://members.aol.com/ajdalton7/screen

Arthur Dalton · #24 09-18-2007, 10:51 AM

Quote:

Originally Posted by Larry Delor

Do the 108's have this flower pot as well?

Which 108..???
Swirl Pots are designed for Injected engines..carb do not need this princible b/c they have a float chamber.
So, 108/Carb did not , but I believe all MFI did...
It uses the electric fuel pumps pressure coming back into the pot from the return line that makes it work. Carb systems had mechanical FP.

Larry Delor · #25 09-18-2007, 11:11 PM

My '71 280SE
Thanks Arthur....unfortunately this has opened up a small can of worms for me. I was hoping that I just had the dirty screen to deal with (I used a hex bolt head to unscrew it), and the tube that runs diagonally to the pump is/was full of crud (tar like substance).
Looks like I have no choice but the get the tank boiled out.

aaown · #26 09-19-2007, 11:35 PM

Quote:

Originally Posted by Larry Delor

As I found out myself, here on the forum, there is another filter in the fuel pump...I believe it is on the inlet side...a small filter, maybe smaller than your pinkie.
How was the tank screen - dirty? so-so?

Is your injection the kind that has the little dipstick?

When it stalls, unscrew the gas cap, and see if you hear hissing (air being sucked in).

Well, the tank screen was discolored, but not clogged. I cleaned it with carb cleaner and it looked good.

I'm not sure if the injection pump has a dipstick, never noticed one. Thanks for the tip on listening for air. I am going to check the fuel flow and go from there.

Al

Ton · #27 07-11-2018, 02:30 PM

Quote:

Originally Posted by aaown

I am at my wits end. I have a 1971 280sl that runs great when you first start it and drive down the road. Take it on the road and run it for 5 to 7 miles at 60mph and it will start to stumble, lose power and eventually stall. Pull over, let it sit for a minute and it will start and run ok for a few minutes and do the same thing all over again. It is running rich as the plugs seem to have some black residue on them, but not wet. I have replaced all filters (air, gas, injection pump), standard ignition items (plugs, wires, cap, rotor, condenser, coil), no help.
Any idea's out there? Please let me know if you have any idea's.

Thanks,

P.S. This car has about 50k on it. It is a 6 cyl with a 4 speed. It has been in storage for about 10 years, being started only occassionally with treated gas.i

.
I have the same issue w111 280se 6 cylinder US led car.
New cap,rotor,points,condenser,plugs,coil,fuel,filter, drained tank new filter in tank.

Ton · #28 07-11-2018, 02:31 PM

I have the exact same issue w111 280se 1969 6 cylinder

Benz Dr. · #29 07-11-2018, 03:49 PM

Common problem.

A note of caution: while blowing air into the return line going back to the fuel tank make sure you have your fuel cap removed. Also, wrap a rag around your air wand where it meets your rubber hose that's connected to the return line. If the return line is plugged, you will have a burst of air coming back out of the line and fuel will spray right into your face.

There is also a return line running across the bottom of the fuel tank. Since it's inside of the tank you won't be able to see it or easily access it. If it's plugged there are ways to open it up but I would have the tank boiled out first to prevent any potential fires or worse.